The invention relates to a musical scoring system capable of producing a musical score by processing note/rest length data and interval data obtained in response to playing a keyboard, and in particular, to a system which accurately quantitizes the length of notes and rests based on such data.
A conventional quantization technique used in scoring systems comprises deriving a quantized value of note or rest from the difference (D.sub.n -D.sub.n-1 .fwdarw.S.sub.n) between a current note/rest length data (D.sub.n) and an immediately preceding note/rest length data (D.sub.n-1) obtained by operation of the keyboard. It will be observed that if timing of the human keyboardist is precise and in accordance with the note and rest values of the music, the resulting score will be correct regardless of the quantization technique employed. Hence, such a system will produce a musical sheet which correctly corresponds to the original from which the music was played in the beat and intervals of the notes and rests. However, playing the keyboard in a precise manner as called for by the original music is almost impossible to a typical player, and, in particular, for a beginner. Accordingly, when a melody played on the keyboard is quantized on a real time basis to form a musical score, a quantization error will result. In particular, when the conventional difference technique mentioned above is employed, the quantization error accumulates gradually toward the end of a measure, resulting in an appreciable deviation in the timing between musical score produced by the actual operation of the keyboard and the timing and meter of the original music being scored. This also means that the alignment with the timing or meter is provided toward the end of the measure. Other difficulties of this technique are that the magnitude of the quantization error cannot be determined until the music being scored is actually played again, and that the editing of the resulting improperly timed musical score is typically very troublesome.